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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      "use strict";
      function makeUser() {
        // let this=undefind;
        return {
          name: "John",
          ref: this,//undefind
        };
      }
      let user = makeUser();//{name:John,ref:undefind}
      console.log(user.ref.name);//undefind.name
    </script>
  </body>
</html>
